1. Field of the Invention
The present invention relates to devices which are used for securing a vehicle in parked position next to a loading dock or platform.
2. Description of the Related Art
A large number of devices have been developed or engaging the ICC bar of the vehicles which are parked next to loading docks or platforms Many of these devices have a restraining member which rotates between locked and unlocked positions. For example, U.S. Pat. No. 4,630,989 to Davey discloses a bar which is rotated between the horizontal and vertical positions by a hydraulic cylinder. A system with a hook member which is rotated by a motor between locked and unlocked positions, and which includes a slip clutch between the drive motor and hook member is disclosed in U.S. Pat. No. 4,692,755 to Hahn. In U.S. Pat. No. 4,634,334 to Hahn, et al., the motor-driven rotatable locking unit rotates about an axis perpendicular to the loading dock so that the locking unit swings in a plane parallel to the loading dock between a position which traps the ICC bar between the locking unit and the loading dock, and a position which allows the ICC bar to move away from the dock. An adjustably mounted toe-like member which extends downwardly to the roadway is disclosed in U.S. Pat. No. 4,560,315 to Hahn. The device includes a rotating hook which is rotated on a sliding carriage which moves up and down for height adjustment. U.S. Pat. No. 4,472,099 to Hahn, et al. discloses a hydraulically operated rotating hook with a manually operated pump for activating the hook. A rotating locking hook which is driven through a clutch-like apparatus by an electric motor is shown in U.S. Pat. No. 4,282,621 to Anthony, et al. U.S. Pat. No. 4,648,781 to Sikora shows a rotating locking hook which is electric motor-chain driven. In most of these devices, the restraining structure is usually either a rotating or pivoting hook or bar.